PRDM1 and infection: (D) Representative histograms of Blimp-1 expression (right) and mean frequency of Blimp-1+ splenocytes (left) among total gated CD4+ T cells from non-infected mice (ctr, gray shaded area and bar) or among CD4+GzB+ (red line and bar) or CD4+GzB- (black line and bar) from WT infected mice at day 14 post-infection (pi).